‘The wicked shall be turned back to Sheol,
Even all the nations who forget God.
For the needy shall not always be forgotten,
Nor the expectation of the poor perish for ever.'
After the pause and the music the final triumphant conclusion is reached. It deals with final principles. The unrighteous, and those who forget God (compare Psalms 50:22; Job 8:13; Psalms 10:4), revealing it by their behaviour, will depart for the world of the grave, into gloom and darkness. They will return to the dust from which they came (Genesis 3:19). That is their inevitable end. On the other hand the needy and the poor will survive and come into God's everlasting blessing, which is their destiny, because He has not forgotten them. They may be forgotten now, but they will not always be forgotten. They may see their cherished expectations dying now, but it will not always be so. In the end the righteous will prevail. For the righteous there will be life, for the unrighteous, judgment and destruction.
Note the change in this verse from YHWH to ‘God'. These are those who have rejected YHWH's offer of mercy, and must therefore face Him as ‘God' over all, the Judge, and not as YHWH the covenant deliverer.
They could have come to YHWH. For we must remember that there was always a way into the covenant for any among the nations who would submit to YHWH, for ‘strangers' were always welcomed if they would but submit to God's Instruction (Torah - Law), and worship Him in the way that He required (Exodus 13:48-49). Thus by refusing this opportunity and choosing to remain as part of ‘the nations' as opposed to ‘God's people' they were rejecting God. That is why ‘the nations' were the unrighteous. They were ‘the world', deliberately turning away from God and His ways, in direct contrast with believers.